Sally Davies:

Drivers who like to check their email or do their make-up at traffic lights, beware.

General Motors, the largest US auto manufacturer by sales, is preparing to launch the world’s first mass-produced cars with eye- and head-tracking technology that can tell whether drivers are distracted, according to people with knowledge of the plans.

Seeing Machines, an Australian group listed in London, has signed an agreement with safety-goods maker Takata to supply GM with tracking devices for up to 500,000 vehicles over the next three to five years.

The gadgets will start by measuring the rotation of the head so they can alert drivers if they are not spending enough time looking in certain areas such as the road ahead or the rear-view mirror.

“Safety doesn’t sell cars – sexy sells cars,” said Ken Kroeger, Seeing Machines’ chief executive. “But once cameras are there, they can be expanded for other features and purposes.”